External Examiner Internal Examiner Head of Dept. Chairperson/Dean

9th Trimester – MBA(Tech)

SVKM’s NMIMS University

I take great pleasure in submitting the report of IXTH trimester technical training in SIEMENSLtd. My training is giving me an exposure to the actual prevailing conditions in the industryand helping me to check the feasibility of the theories learnt during my engineering studies.

A lot of people helped me in this training and I would like to thank them all. I am grateful toMr. Abhijeet Deherkar (Personnel Dept), SIEMENS LTD. - KALWA WORKS for givingme the opportunity to undergo training in this esteemed organization.

I would like to thank Mr. Mangesh Patil, Mr. S. Tellis, Mr. G.K. Srinivasan and allworkmen for their co-operation and guidelines, which made my training process continualand exciting. I would like to thank them for believing in me, giving me the support,encouragement and guidance, which helped me in carrying out my training successfully. It isindeed a moment of great pleasure and immense satisfaction for me to express a sense ofprofound gratitude and indebtedness to all the people on the shop floor, who contributed inmaking my Training a rich experience.

There Is More to a SIEMENS

Sr. No. Topic Page No.

1 Introduction to Siemens 8

2 Introduction to Value Stream Mapping 23

3 Press Shop 34

4 Winding Shop 44

5 Machine Shop 54

6 Assembly Shop 63

7 Results 73

8 Bibliography 74

6 Synopsis

During my training of three months at Siemens Ltd, Kalwa Works, I was posted in theManufacturing department under the guidance of Mr. Mangesh Patil. I was entrusted with theproject of Value Stream Mapping. For performing the Value Stream Mapping at the shop floor I had to understand themanufacturing procedures on the shop floor thoroughly. Also I had to understand the flow ofmaterial as well as the information on the shop floor. Based on my understanding of themanufacturing processes I had to map the processes on the shop floor and create a currentstate map of the processes in each shop. Based on the current state maps I was supposed to find the defects in the presentsystem and also find a solution to correct them. After correction I also had to take thefeedback from the production planning department and the process planning department.Based on their feedback I had to develop the future state map and also had to check thefeasibility of the same by discussing it with the shop incharges and the workers. Post the feedback from the workers I had to make the necessary changes the futurestate map. Also the recommendations were to be implemented in the shop in a decided order. My main target during the training was to ensure that the waste in the manufacturingprocesses of the motor were reduced to the minimum possible level without disturbing theflow of the material and information on the shop floor.

within the space of a few decades from a small precision-engineering workshop, producingmechanical warning bells for railways, wire insulation made of gutta-percha, and electricaltelegraph systems, into one of the world‟s largest companies in electrical engineering andelectronics. Landmark inventions, an immense readiness to innovate, and a stronginternational commitment have driven the company‟s success since its very beginnings.

When in 1866 Werner Siemens (known as Werner von Siemens after 1888) discoveredthe dynamoelectric principle, the potential applications for electricity were limitless. Heavy-current engineering began to develop at a breathtaking pace, producing one triumphantinnovation after another. In 1879, Siemens & Halske presented the first electric railway and installed the first electric streetlights in Berlin; in 1880 came the first electric elevator; and in 1881 the electric streetcar. Following the death of the company‟s founding father, Werner von Siemens, in 1892, his successors followed the course he had set, constantly advancing the company with trailblazing innovations.

Lighting, medical engineering, wireless

communication, in the 1920s and , household appliances, were followed after World War II by components, data processing systems, automotive systems and semiconductors. The guiding principle that had applied since the company‟s beginnings - of concentrating solely on electrical engineering, "but on the whole of electrical engineering" - helped make Siemens the only company in its industry to operate in both light- and heavy-current electrical

8engineering, and by the mid-1920s it was again one of the world‟s five leading companies inits field.

When the National Socialists seized power, Siemens, like the rest of German industry,was drawn into the system of the war economy. Post World War II, Siemens beganrebuilding in Germany first, but gradually moved into foreign countries from the 1950s on.Technological advances, expansion into new business segments, and the reestablishment of apresence in traditional export markets laid the foundations for the company's return to its oldstrength in the world marketplace in the 1960s. To give the company a stronger identity andconsistent market presence, Siemens & Halske, Siemens-Schuckertwerke AG, and Siemens-Reiniger-Werke AG, the three main companies in the group, merged in1966 to form SiemensAG. Today, Siemens is a transparent organization comprising fast-acting business units thatis making important and significant contributions to the future of electrical engineering andelectronics.

9 HISTORICAL PERSPECTIVE

1857 - SIEMENS found in GERMANY.

1867 - SIEMENS first linkage in INDIA.1954 -Assembly and repair undertaken in small workshop under Mahalakshmi Bridge

Bombay.

1957 - Switchboards manufacturing began at Worli, Bombay.

1959 - Medical equipments added to the range at Worli.1960 - Manufacturing of Switchgear began at Worli, Bombay.1963 - Switch board manufacture transferred to Chakala, Andheri.1966 - First batch of Electric Motors produced at Kalwa.1973 - Transfer and expansion of Switchgear production at Kalwa.1975 - Transfer and expansion of Switchboard production at Kalwa.1977 - Manufacturing of electronic equipments at Worli, Bombay.1984 - Manufacturing of Switchboard started at Nasik.1986 - Manufacturing of Railway Signaling Products.1986 - Heavy investment in Tool room and production shop with the inception of NC and CNC machine.1991 - New Switchgear factory in Aurangabad.

SWITCHBOARD PLANT: SIEMENS switchboards have established remarkable leadership in the market. Thishappens through a deep understanding of the customer‟s requirement, resulting in customer-oriented products design manufactured with latest technology at par with internationalstandard. This unit manufactures switchboards and circuit breakers with different ranges. Theswitchboard is an electrical panel consisting of elements like potential transformers, currenttransformers, circuit breakers, timers etc.

MOTOR PLANT:

The motor factory produces high quality motors with economical energyconsumption, resilient enough to withstand wide voltage and frequency fluctuations. Thefactory is equipped with dedicated and general-purpose CNC machines that ensure accuracyat the micron level. Computerized on the line production planning and control system ensuresa built in quality from the very beginning. The factory has been awarded the ISO-9001certification.

11ROLE OF VARIOUS DEPARTMENTS IN MOTORS: These are the various departments which contribute towards achieving a completefinished product besides the ones on the shop floor viz.

13DESCRIPTION OF SIEMENS MOTOR: Siemens motors are high quality machines with economic power consumption and areresilient enough to withstand wide voltage and frequency fluctuation, a condition widelyprevalent in India. The user-friendly designs are proof of the fact that Siemens has aconsiderable knowledge of the industries, which use their motors.

Induction motors manufactured by Siemens Ltd. are robust in construction and

streamlined in appearance. They are designed, manufactured and tested to high technicalstandards and are suitable for all general, industrial and agricultural application.

The three phase induction motors are available from 5.5 kW to 1.875 MW in thesynchronous speed of 750, 1000, 1500, and 3000 R.P.M. These motors have been approvedby ISI and conform to IS: 325 / 1978 for electrical performance and to IS: 1231 / 1967 fordimensions and are provided with standard class F insulation.

Motors are provided with PTC (Positive Temperature Co-efficient), BTD (BearingTemperature Detector) and ACH (Anti Condensation Heater) in the stator winding as aprotection circuit wherever specified. These motors are of TEFC, TENC, DP, and TEAOMtype. The housing is provided with ample cooling fins evenly distributed over the completesurface for better heat dissipation. For easy handling a lifting hook is provided on the top ofthe casting. The motors have an Aluminum pressure die-cast or copper bar rotor and aredynamically balanced. A uniform rotor - stator air gap and vibration free operation ismaintained generally conforming to IS: 4769 / 1968. The rotor is specially treated for rustprevention, i.e. a coat of red oxide is applied over the balanced rotor.

In this type of construction, the motor is equipped with the foot as

well as flange. The flange is coupled to a coupling. The position of

the shaft in this type of construction is horizontal.

In this type of construction, the foot of the motor is clamped to a vertical

surface. The position of the shaft is vertically downwards. This is also a

foot-mounted motor.

18IMV6 CONSTRUCTION

In this type of construction, the foot of the motor is clamped to vertical

surface. In this type, the position of the shaft is vertically upwards. This is a

foot-mounted motor.

IMB6 CONSTRUCTION

In this type of construction, the position of the shaft is towards the right of the

foot, which is mounted on the wall. This is also a foot-mounted motor.

IMB7 CONSTRUCTION

In this type of construction, the position of the shaft is towards the left of the

foot, which is mounted, on the wall. This is also a foot-mounted motor.

IMV1 CONSTRUCTION

In this type of construction, there is a flange being mounted. The direction of

the shaft of the motor is vertically downwards. In this type there is no IMVI

mounting foot provided.

19BASIC PRINCIPLE: -

When the three phase stator windings are fed by a three-phase supply, a magnetic flux ofconstant magnitude but rotating at synchronous speed is set up. The flux passes through theair gap, sweeps past the rotor surface and cuts the rotor conductors. Due to the relative speedbetween the rotating flux and the stationary conductors, an electromotive force is induced inthe conductors, according to the Faradays law, because of the closed circuit rotor, a rotorcurrent is produced whose direction as given by the Lenz‟s law (“it opposes the very causeproducing it”). The cause here is the relative speed between the rotating flux of the statorand the stationary conductor of the rotor. Hence to reduce the relative speed, the rotor startsrotating in the same direction as that of the flux and tries to catch up with rotating flux. Theshaft through the rotor is used to transmit the rotary mechanical power to drive machines.

20Induction AC MotorsAC motors typically feature rotors, which consist of a laminated, cylindrical iron core withslots for receiving the conductors. The most common type of rotor has cast-aluminumconductors and short-circuiting end rings. This AC motor "squirrel cage" rotates when themoving magnetic field induces a current in the shorted conductors. The speed at which themagnetic field rotates is the synchronous speed of the AC motor and is determined by:

Ns = 120*(f/p)

Where,Ns = Synchronous speedf = Frequency, andp = Number of Poles.

2122 CHAPTER 2

Introduction to Value Stream Mapping

A Value Stream is the set of all actions (both value added and non value added)required in bringing a specific product or service from raw material through to the customer.

Value Stream perspective means working on the big picture, not just individual processes,and improving the whole, not just optimizing the parts. Value Stream is a pencil paper toolthat helps one to see and understand the flow of material and information as a product makesits way through the value stream.

The value stream mapping (VSM) method is a visualization tool oriented in ToyotaProduction System (TPS). It helps to understand and streamline work processes by using thetools and techniques of lean manufacturing. The goal of VSM is to identify, to demonstrateand to decrease waste in the process. Waste is defined as any activity that does not add valueto the final product. VSM can thus serve as a starting point to help Managers, Engineers,Production Associates and Schedulers to recognize waste and identify its causes. As a result,VSM is primarily a communication tool, but it can also be used as a strategic tool

In order to do this, the VSM method visually maps the flow of material and information.From the moment products are entering the back door as raw materials, via all manufacturingprocess with cycle time until the product leaves as a finished product.

Mapping the processes with cycle time, down time, in-process material movement,information flows, helps visualize current state of process activities and guides toward thefuture desired state. The process usually includes mapping the “current state” and the “futurestate”. These then serve as a foundation for other lean manufacturing strategies.

23 History of Value Stream Mapping

The use of waste removal to achieve competitive advantage inside organizations waspioneered in the 1980s by Toyota's chief engineer, Taiichi Ohno, and sensei Shigeo Shingoand is oriented fundamentally towards productivity rather than towards quality. The reasonfor this is thought to be that improved productivity leads to leaner operations which help toexpose further waste and quality problems in the system. Thus the systematic attack on wasteis also a systematic assault on the factors that are underlying poor quality and on fundamentalmanagement problems.

The seven commonly accepted wastes in the Toyota production system were originally:

 Process activity mapping.

 Analyze the process and record all the details like distance, time and people.  Classify processes as operation, transportation, inspection, delays, storage and identifies cycle time, set-up time and manpower.  Trace production flow and/or information flow  Simplify the flow by eliminating and/or combining the activities.

 Supply chain response matrix.

 Determine lead time for a product internally and externally

 Determine the average amount of standing inventory at specific points in the supply chain.  Reduce both the lead-time and standing inventory.

 Production variety funnel.

 Plot number of variants at each tier of suppliers

 Help in understanding of how the supply chain operates for the given product  Identify buffer stock of various components and subassemblies.  Decide where we can reduce inventory and make change in processing of products.

 Quality filter mapping.

 Identify where quality problems exist in value stream.

 Classifies defects as product, service or internal scrap.  Analyzes where in the supply chain defects occur.  Establishes both internal and external quality levels.

 Demand amplification mapping.

 Determine where in the value stream, the flow goes from push system to pull system.  Help in analyzing the „what if‟ scenarios to view the operation of value stream when the decision point is moved along the value stream for better design.  Analyze where in value stream excess inventory exist.

 Physical structure mapping.

 Provide an overview of the value stream.

 Determine how the cost structure and volume structure look like along the value stream. In both the structures assembler is located in middle of supplier tiers and distribution tiers.  Help in finding waste due to the overall structure of industry and eliminate the waste.  Requirements

26Symbols used in value stream mapping

VSM Process Symbols

This icon represents the Supplier when in the upper left, the usual starting point for material flow. The customer is represented when placed in the upper right, the usual end point Customer/Supplier for material flow.

This icon is a process, operation, machine or department,

through which material flows. Typically, to avoid unwieldy mapping of every single processing step, it represents one Dedicated Process department with a continuous, internal fixed flow path.

This symbol indicates that multiple processes are integrated in a

manufacturing workcell. Such cells usually process a limited family of similar products or a single product. Product moves Workcell from process step to process step in small batches or single pieces.

VSM Material Symbols

These icons show inventory between two processes. This icon also represents storage for raw materials and finished goods.

Inventory This icon represents movement of raw materials from suppliers to the Receiving dock(s) of the factory. Or, the movement of finished goods from the Shipping dock(s) of the factory to the customers Shipments This icon represents the "pushing" of material from one process to the next process. Push means that a process produces something regardless Push Arrow of the immediate needs of the downstream process. This is an inventory 'supermarket" (kanban stockpoint). Like a supermarket, a small inventory is available and one or more downstream customers come to the supermarket to pick out what they need. The upstream workcenter then replenishes stocks as required. When continuous flow is impractical, and the upstream process must operate in Supermarket batch mode, a supermarket reduces overproduction and limits total inventory.

First-In-First-Out inventory. Use this icon when processes are connected

with a FIFO system that limits input. An accumulating roller conveyor is an example. Record the maximum possible inventory. FIFO Lane This icon represents an inventory "hedge" (or safety stock) against problems such as downtime, to protect the system against sudden fluctuations in customer orders or system failures. Notice that the icon is closed on all sides. It is intended as a temporary, not a permanentSafety Stock storage of stock; thus; there should be a clearly-stated management policy on when such inventory should be used.

Shipments from suppliers or to customers using external transport.

External Shipment

VSM Information Symbols

This box represents a central production scheduling or control

Production department, person or operation. Control This icon is used whenever the on-hand inventory levels in the supermarket between two processes drops to a trigger or minimum point. When a Triangle Kanban arrives at a supplying process, it signalsSignal Kanban a changeover and production of a predetermined batch size of the part noted on the Kanban. It is also referred as "one-per-batch" kanban.

A location where kanban signals reside for pickup. Often used with two-card systems to exchange withdrawal and production kanban.Kanban Post

28 VSM General Symbols

This icon represents an operator. It shows the number of operators

required to process the VSM family at a particular workstation.Operator

Other useful or potentially useful information.

Other The timeline shows value added times (Cycle Times) and non-value added (wait) times. Use this to calculate Lead Time and Total CycleTimeline Time.

29WHERE CAN VALUE STREAM MAPPING BE USED?

Value Stream Mapping is commonly used in Lean environments to identify opportunities forimprovement in lead time.

Although Value Stream Mapping is often associated with manufacturing, it is also used inlogistics, supply chain, service related industries, healthcare, software development, andproduct development.

The value adding steps can be drawn across the centre of the map and the non-value addingsteps be represented in vertical lines at right angles to the value stream. Thus the activitiesbecome easily separated into the value stream, which is the focus of one type of attention andthe „waste‟ steps, another type. Value stream is the process and the non-value streams theoperations. The thinking here is that the non-value adding steps are often preparatory ortidying up to the value-adding step and are closely associated with the person ormachine/workstation that executes that value adding step. Therefore each vertical line is the'story' of a person or workstation whilst the horizontal line represents the 'story' of the productbeing created.

30 WHY TO USE VALUE STREAM MAPPING?

 It helps you visualize more than the single process level i.e. the whole process flow. Mapping helps you not only see waste but also the source of waste in the value stream. Provides a common language for talking about manufacturing processes. It ties together lean concepts and techniques. It shows the linkage between information flow and material flow.

SCOPE OF VALUE STREAM MAPPING

The project is aimed at mapping understanding the current processes of induction

motors and windmill generators manufacturing. Thus VSM will give the current state maps. Current state maps will enable locating waste in form of inventory, waiting time, transportation and overproduction at every step of the manufacturing process. From this mapping we shall derive the future state maps which shall have minimum possible manufacturing waste.

31 STEPS IN VALUE STREAM MAPPING

Value stream mapping consist mainly of four steps, viz.

1. Selecting a product or product family:

Before starting the value stream mapping process one product or product family is to be selected which will be mapped. Mapping all the products together is not possible because drawing all the product flows on one map will be complicated, unless one has a small one product shop floor. Value stream mapping means walking and drawing the processing steps (material and information) for one product family (group of products that pass through similar processing steps and over common equipment in downstream processes) from door to door in the plant.

2. Create a current state map:

Mapping begins at the level of door to door flow in the plant. Current state mapping includes mapping the process categories instead of recording each processing step. Symbols or icons shown before are used to represent the process and flows. Some tips to be used while mapping the current state:

I. Information regarding the current state should always be collected by walking along the pathway of material and information flow.II. Begin at the shipping end and work upstream instead of starting at the receiving dock and walking downstream.

3. Create the future state map:

The purpose of value stream mapping is to highlight sources of waste and eliminate them by implementing the future state within a short period of time. The purpose is to build a chain of production where every process is linked to their customer(s) either by continuous flow or pull and each process gets as close as possible to produce only what its customer need and only when they need it.

32 To prepare the future state a list of questions is needed like:

 Will the workstation produce to a finished goods market where a customer just pulls or directly to ship to customer?  Where can you use continuous flow processing?  Where will you need a supermarket pull system?  At what point in the production chain will you need production planning?  What process improvements will be necessary?

4. Achieving the future state map:

Value stream mapping is just a tool. Unless one implements the future state that he/she has drawn, the value stream mapping is useless. In implementing the future state map the map is broken into steps and the implantation sequence is developed.

33 Chapter 3

PRESS SHOP

Press shop is the origin of motor manufacturing. The shop has dynamo steel coils as inputs which are then converted to blanks and processed further to give stator packets and die cast or copper bar rotors as output.

The processes in the press shop are as under:

a. Blanking:

Stator blanks are created in this operation from the coiled dynamo steel sheets. One machine at this workplace satisfies the requirement of the entire plant. The shaft hole is also punched out from the blank in the operation.

b. Stator Notching:

The Blanks from the previous operation are the input to the process. There are four stator notching machines in the shop. Some of the laminations of higher sizes are outsourced. The notched stator lamination is then further sent for stator packetting and the rotor blanks are sent for rotor notching.

34c. Rotor Notching:

The rotor blanks from the stator notching operations are the inputs to this operation. There are four rotor notching machines in the shop. Some lamination notching operations are outsourced. The notched laminations are then sent for either die casting or preheating for shaft insertion.

d. Stator Packetting:

The notched laminations are converted into packets of desire height. There are three pressing machines which cater to the needs of the packets. The stator packets after deburring would be sent to the winding shop for stator winding and impregnation process.

e. Die Casting/Copper bar Insertion:

The Rotor laminations after notching are sent for either aluminum die casting or copper bar insertion. After this operation they would be sent to the machine shop for turning / shaving operation.

35 OBSERVATIONS

1. After the stator notching operation the laminations are kept without arranging on the table.2. After the packeting operation the small stator packet go to the deburring section on a conveyor but the large packets have to be transported on forklift.3. The inventory at every workstation was enough to last for about 3 to 3.5 shifts.4. Motor of frame size 25, 28, 31 four pole comprise of 75% to 80% of production. Hence to control inventory these motors have to be targeted.5. Whenever a die is set on the blanking machine approximately 100,000 to 150,000 blanks are created and then the die is send for regrinding. The die set once sent to the tool room for regrinding takes about 8 days to be operational again.

Based on the observations made in the press shop the current state mapping (1LA0 254-4, 1LA0 284-4 and 1LA0 314-4 motors) of the operations in the press shop is done.

36373839 RECOMMENDATION

1. After notching the stator laminations, the laminations should be kept in a fixture which can directly be used for stator packeting. This would save the time in arranging of laminations. This would result in reduction of stator packeting time by about 15%. This would also result in rationalizing the SMH by about 600 hours per annum.2. A passage to be formed between the packeting area and the deburring station so that stator packets with bigger frame size can be transported with the help of a Jib crane to reduce material movement.3. Instead of having 100,000 to 150,000 blanks WIP inventory at a time. We can have 30,000 to 40,000 blanks and then send the die for regrinding. This will prevent heavy grinding cuts and also would act as a preventive maintenance for the die set.4. Kanban to be implemented between the stator notching & packetting and Die Casting & Rotor notching work stations. This will ensure no production planning is required in either stator or rotor notching.5. Also there has to be synchronous manufacturing between stator packetting and coil manufacturing in winding shop and rotor notching and keyway milling operation in the machine shop. Hence a signal kanban has to be send from stator notching or stator packetting to the respective shops.

Based on the recommendations above the future state map (1LA0 254-4, 1LA0 284-4 and 1LA0314-4) is prepared.

40414243 Chapter 4

WINDING SHOP The Stator packets from the press shop are the inputs to this shop and varnished winding packets are the output to the assembly shop.

The operations in the winding shop are:

a. Coil Winding:

Coils are made on the coil forming machine. There are five machines which satisfy the requirement of the entire plant.

b. Insulation Preparation:

At this workplace phase insulation papers are cut as per requirement. Motor type starting from 1LA025 up to 1.875MW can be prepared at this workplace.

c. Stator Winding:

The coils prepared in the coil winding operation and the stator packets from the press shop are the input to this operation. The coils are inserted into the packet as per the drawing made on customer requirements. The finished stator packet is then send for the connection operation

44d. Connection:

Stator windings from the previous operation are the input for this operation. The phase connections are done and the lead cables are connected as per the drawing from the design department. After this the stator packet is sent for connection testing.

e. Impregnation:

Vacuum Pressure Impregnation (VPI) completely seals the windings against moisture and vibration and provides greater mechanical strength. Stator winding after the connection procedure is the input for this process. After impregnation the stator packet is sent for curing in an oven and is then sent to assembly shop after scraping off the excess resin on the packet.

45 OBSERVATIONS

1. There are 5 coil winding machines, all capable of making all the types of coils. Setting time contributes to 20% of total time. Also spool change time contributes to 5% of total time.

2. There are ten different types of wires of which six are used 97% of time.

3. In insulation cutting to, 22% of total time is setting time.

4. After stator winding the coil is sent to the connection station for phase connections because all the worktables are not equipped with connection facilities. As a result there is WIP inventory before the connection station.

5. Coil manufacturing starts only when the packet is ready and is released from the press shop.

Based on the observations made in the winding shop the current state map (1LA0 254-4, 1LA0284-4, 1LA0 316-4) is drawn:

46474849 RECOMMENDATIONS

1. In coil winding operation the coil winding machines to be standardized for making a coil for a motor type and a particular size of copper wire. This will reduce the setup time by almost 70%.

2. Changeover from 90 kg to 180 kg size copper spools to improve machine utilization. Also as the spool capacity has doubled the downtime of the machine will become half and would hence save 200 to 300 SMH annually.

3. Also since the spool capacity is doubled the area for copper storage is reduced to half.

4. Synchronous manufacturing of coil and stator packet is recommended in order to save on the additional lead time of coil manufacturing.

5. As Motor of frame size 25, 28, 31 four pole comprise of 75% to 80% of production the insulation of this motors of every size to be cut and kept at least 10 in number. Also kanban to be implemented for withdrawal of the insulation. As the quantity reduces to 5, a trigger will be sent to refresh the insulation quantity to 10.

6. The operator doing the stator winding operation should also be trained in doing the connection operation. Hence oxy-acetylene flame torches to be provided at every workstation. This will also save 800 SMH per annum.

7. Pre heating of winding should be done with DC electric current. It will save about three hours per job.

8. The curing of winding after impregnation to be done with DC electric current will save about five hours per job.

Based on the recommendations made the future state map of the winding shop is as follows:

50515253 Chapter 5

MACHINE SHOP The die cast or copper bar rotors from the press shop are the input to this shop and the finished rotor is the output to the assembly shop.

The operations carried out in machine shop are:

a. Shaft centering facing and tapping:

The raw shaft from the vendor is loaded on the centering machine and the facing operation is done first. The shaft is then sent for centering and after that the tapping is done to facilitate easy lifting of shaft with help of eye bolt.

b. Shaft turning:

The shafts from the previous operation are the input to this operation. The shaft is loaded between the centers and turned as per the drawing given by the design department. These shafts are then sent for key way milling operation.

c. Keyway milling:

The shafts after the turning operation are sent to keyway milling operation. There is just one machine for keyway milling which serves the need of entire plant. These shafts after keyway milling are sent to the press shop.

d. Rotor turning:

Rotors from the press shop are the input to this operation. The die cast or the copper bar inserted rotors are the input to this operation. The rotors are turned as per the specification in the drawing, deburred. Post this operation red oxide is applied in order to prevent rust and sent to grinding.

54e. Shaft grinding:

After the rotor turning operation the rotor is sent for grinding. Parts where the pulley is fitted on both the ends and also the keyway part is grinded to achieve the exact dimensions and surface finish. Post this operation the rotor is sent to assembly line for motor assembly.

OBSERVATIONS

1. The lathe on which shaft is turned is placed on the other end of the gangway. As a result the shaft coming into the shop has to travel through the gangway in order to reach the machine.

2. The lathes on which the die cast rotors from the press shop are turned are placed on the entrance of the gangway. As a result the die cast rotors have to travel through the entire gangway of either press shop or machine shop in order to reach the respective machine.

3. There is large amount of finished inventory kept in the shop which cannot be dispatched to assembly because of unavailability of finished stator packets.

Based on the observation in the machine shop the current state map is drawn:

55565758 RECOMMENDATIONS

1. There has to be a single line flow between the turning and the grinding operation in order to prevent and WIP in between the two operations.

2. The Becco lathe on which shafts are turned should be moved to the TSDC end of the gangway in order to prevent the shaft to travel the whole gangway. This will save around 44 meters of material transport per shaft.

3. Similarly the die cast rotors from the TCS die casting machine are turned on two lathes, viz. Rotor and Enterprise. These lathes to be moved from the start of the gangway to the winding shop end. This will save around 74 meters of material transport per die cast rotor.

4. Also a passage, if possible is to be built between the TCS die casting machine and these two lathes would reduce the material transport further by 34 meters.

5. The rotors are only to be finished i.e. deburring, grinding and applying antirust when the respective stator packet goes for curing operation. This will reduce the finished goods inventory in the machine shop. This would also prevent waiting for both the stator and the rotor in the respective shop thus resulting to effective space utilization.

Based on the recommendations the future state map of the machine shop is as follows:

59606162 Chapter 6

ASSEMBLY SHOP The final station in motor manufacturing process is the assembly shop. The shop gets input from the winding shop (Stator Packet) and from the Rotor shop. Also there are a lot of outsourced products such as end shield, bearing, motor housing etc from various vendors.

The operations carried out in assembly shop are:

a. Packet Pressing:

The finished stator packet from the winding shop and the motor housing from the outsourced vendor are the input to this operation. The housing is loaded on the pressing machine and the packet is pressed into it. This housing is then loaded on a separate table for terminal connections.

b. Terminal Box Assembly:

The leads coming out of the stator packet are taken out from a terminal box and connected and the necessary terminals are shot together. The input to the motor is given from the terminal box and the output terminals (in case of the generators) are also taken from the box.

c. Auxiliary Terminal Box Assembly:

The additional features of a motor whose lead cables come out of the winding are connected in a separate terminal box known as auxiliary terminal box. It includes the connections of Anti Condensation Heater (ACH), Bearing Temperature Detector (BTD), Positive Temperature Co-efficient (PTC), etc.

63d. Rotor Balancing:

Rotor from the machine shop is the input to this operation. As a rotating machine the rotor need to have even weight distribution on both the sides (to prevent vibrations) and is hence balanced on a dynamic balancing machine. This rotor after balancing is then sent to the motor assembly station for Bearing Assembly.

e. Bearing Assembly:

Balanced rotor is the input to this operation. The bearing assembly includes three parts on either side of the rotor which are shrink fitted after induction heating for three hours at about 120°C. The bearing assembly consists of three parts viz.

i. Inner bearing cover

The rotor with the bearing on each side is inserted into the stator housing and the end shields are fitted on both ends of the shaft.

g. Fan Assembly:

This is the last operation in the motor manufacturing operation. The cooling fan is shrink fitted on the B-side (non-output side) of the rotor in this operation. The fan cowl (fan cover) is then fixed on this end above the fan.

64 OBSERVATIONS

1. There is a large amount of finished rotor inventory kept in the racks in the assembly shop.

2. The terminal boxes required on each motor is as per customer specification and hence a large variety of terminal boxes are available.

3. The waiting time of components due to non-availability of specific required terminal box is high

4. There is almost a 3 day WIP in the shop of Grade C items.

5. A large number of motors are waiting for acceptance testing from the customer.

Based on the observations the current state map is drawn:

65666768 RECOMMENDATIONS

1. The terminal box should be assembled offline and then directly fitted onto the motor.

2. One drilling machine should be procured in assembly shop such that standard terminal box will be procured and non-standard drilling will be done in assembly as and when required. This will reduce the waiting time for all the components consecutively.

3. A kanban system to be developed between assembly shop and machine shop to pull the rotors from the shop when required and not stock inventory in the shop

4. Also a kanban system to be developed between the stores and the assembly shop in order to control Grade C items inventory.

5. Motor assembly to be done only a day or two in advance of customers consent for motor testing

Based on the recommendations the future state map is drawn.

69707172 Results1. 600 SMH saved in press shop by the use of fixture for stator laminations during packetting operation.

2. Standardizing the coil winding machine will also reduce the setup time by 70%.

3. Changeover from 90 kg to 180 kg copper spools saves about 3000 kg of copper scrap annually, reduce the area required for copper storage to half the current area and gives SMH rationalization of about 300 SMH annually by reducing the frequency of changing the spools.